1. Field of the Invention
The present invention relates to a composite material composition comprised of a constitutional element having biodegradability, and more specifically relates to a composite resin composition which has high processing ability on processing said composition, provides resulting processed articles having excellent mechanical strength and biodegradability, and can be effectively utilized for a film, sheet, tray and other one-way formed articles, furniture parts, construction materials, interiors for motor vehicle and household electrical appliances, and housing applications.
2. Description of the Related Art
Cellulose, wood, starch and other biomass materials have poor thermoplasticity and powdered materials, in particular, have been difficult to process by hot-press plastic forming as intact into boards and sheets.
Consequently, wood flour, in particular, which is a waste matter and exists on a huge amount is limited to utilization in a field of low added value such as straw mulching for cattle breeding and other farm and dairy materials and fillers. In the extreme cases, wood flour is burned without utilization.
Further, wood flour was utilized in Japan until several years ago as a raw material of activated carbon. The utilization was considered useful in view of environmental conservation. However, due to low degree of processing, import of the activated carbon from South East Asia and China is now increased and domestic products are extremely decreased.
Also as to the cellulose based waste, effective utilization of waste paper is not necessarily progressed. Development of new techniques for the practical application of waste paper is now desired in relation to fill out and effective date of recycle act which has now received attention (on waste paper and paper box, in the year 2000 A.D.).
As to starch, new development of practical use for various purposes other than foods has been desired in view of the present situation on the balance of world-wide demand or in consideration that there is space for increasing supply of starch.
From a still higher standpoint, a way of thinking that an organic material system using plant resources and cereals as a raw material will be required in the near future in order to apply a brake on the use of petroleum is beginning to sprout. As a fundamental response to such situation, it should be needed to have a sense of problem that an application technique of a biomass material will be steadily made up from the base.
Consequently, various investigations have been carried out on a high-grade utilization or a large-scale application of biomass materials. A typical example includes a molding material obtained by melt-kneading a thermoplastic resin with wood flour.
However, on the basis of the conventional technique, such a molding material prepared from thermoplastic resin and wood flour has been unsatisfactory to dispersibility, compatibility, adhesion ability of wood flour surface to matrix resin and mechanical property.
As a result of an intensive investigation in view of these problems, the present inventors have found that these problems can be solved by employing a modified resin for the matrix resin. That is, the present inventors have disclosed in Japanese Laid-Open Patent SHO 62-039642 a technique concerning a composite resin composition which is obtained by formulating a specific proportion of modified polyolefin, cellulosic material and specific graft compound, is extremely excellent in mechanical strength and also excellent in transparency and smoothness and suitable for interiors such as films, sheets and furniture.
Many investigations have been conducted on the application of the technique. As a result, an artificial wood of markedly high durability prepared by extrusion-forming a wood flour/thermoplastic resin composite kneaded material has come to be effectively used as a residential part.
These techniques use wood and other biomass materials as a filler and employ polypropylene, polyethylene, polyvinyl chloride, ABS resin and other general purpose resins for a matrix resin. It is thus very significant when good durability is required.
However, in consideration of the final waste disposal treatment after finishing use, the waste remains semipermanently in the environment when landfilled and emits hazardous wastes into the environment when incinerated.